Replacing feed rollers with rubber tubing

[onWARD]

I'm considering using automotive or food-grade rubber tubing to replace gooey, petrified feed rollers. I've found food-grade silicone (shore 70A) and nitrile fuel hose in the right diameters. My main concern is how these materials might interact with the platen, could they cause damage?

 

[TwoHeaded_Bear22]

I'm considering using automotive or food-grade rubber tubing to replace gooey, petrified feed rollers. I've found food-grade silicone (shore 70A) and nitrile fuel hose in the right diameters. My main concern is how these materials might interact with the platen, could they cause damage?

I've seen this fuel hose repair method discussed before. My primary concern wouldn't be immediate damage but the long term effects. Nitrile and silicone aren't engineered for the specific friction and material compatibility a typewriter mechanism requires and may harden or chemically interact with the platen rubber over yrs of use. What's the main driver for attempting a material substitution instead of using a specialty service to recover the rollers with the correct type of rubber?

 

[Overwood]

Or you could probably buy something appropriate from JJ Short

 

[phdezra]

I've seen this fuel hose repair method discussed before. My primary concern wouldn't be immediate damage but the long term effects. Nitrile and silicone aren't engineered for the specific friction and material compatibility a typewriter mechanism requires and may harden or chemically interact with the platen rubber over yrs of use. What's the main driver for attempting a material substitution instead of using a specialty service to recover the rollers with the correct type of rubber?

@TwoHeaded_Bear22

You're right that fuel hose and silicone weren't engineered with platen interaction in mind. In practice, they can sometimes "work" for a while, but the feed rollers are doing very delicate duty: gripping, advancing, and releasing paper at precisely the right tension. The wrong compound may harden, glaze, or leave chemical traces that the platen rubber won't forgive over years of use.

That said, I'll admit part of the attraction here is curiosity and availability—I've got some tubing on hand, whereas proper roller recovering means sending things away, waiting, and spending a fair bit more. It's not that I doubt the value of professional re-rubbering (that's still the gold standard), only that I wanted to explore whether a stopgap could be serviceable for a machine that won't see daily pounding.

Ezra

 

[Tortured Poets Department]

@onWARD Totally get the curiosity angle, and experimenting can be fun, but long-term platen health is tricky. If you go the tubing route, just keep an eye out for glazing or hardening over time.

 

[TwoHeaded_Bear22]

@TwoHeaded_Bear22

You're right that fuel hose and silicone weren't engineered with platen interaction in mind. In practice, they can sometimes "work" for a while, but the feed rollers are doing very delicate duty: gripping, advancing, and releasing paper at precisely the right tension. The wrong compound may harden, glaze, or leave chemical traces that the platen rubber won't forgive over years of use.

That said, I'll admit part of the attraction here is curiosity and availability—I've got some tubing on hand, whereas proper roller recovering means sending things away, waiting, and spending a fair bit more. It's not that I doubt the value of professional re-rubbering (that's still the gold standard), only that I wanted to explore whether a stopgap could be serviceable for a machine that won't see daily pounding.

Ezra

You explained well the difference between a full restoration and a quick fix for a lightly used machine. Your point about the rollers' delicate job is important, since the right hardness helps grip the paper without causing harm. I'm curious if @onWARD had this in mind. On a related note, has anyone found a modern tubing material with a shore hardness that's softer than the usual 70A and suitable for feed rollers?

 

[qwertycollector]

Food-grade silicone with a durometer of 70A should be safe to use on the platen since it's softer than the original rubber rollers. Nitrile, on the other hand, might be too stiff and could potentially harm the platen surface. It's a good idea to test the silicone on a small section first. Also, ensure that whatever material you choose has the appropriate coefficient of friction for smooth paper feeding.